Apparatus for removing dust from paper webs



Jan. 22, 1963 R. K. REMER APPARATUS FOR REMOVING DUST FROM PAPER WEBSFiled Feb. 4, 1959 3 Sheets-Sheet 1 2 INVENTOR. ROBERT K. REMER BY 4 9Jan. 22, 1963 R. K. REMER APPARATUS FOR REMOVING DUST FROM PAPER WEBS 3Sheets-Sheet 2 Filed Feb. 4, 1959 iNVENTOR. EQ BERT K. REMER B flmxi rF-Hg R. K. REMER Jan. 22, 1963 APPARATUS FOR REMOVING DUST FROM PAPERWEBS 3 Sheets-Sheet 3 Filed Feb. 4, 1959 INVENTOR.

K. REMER ROBERT BY A United States Patent 3,674,6 Patented Jan. 22, 19633,074,036 APPARATUS FOR REMOVENG DUST FROM PAPER WEES Robert K. Rainer,Elgin, 111., assignor to Tribune Company, Qhicago, 111., a corporationof lilinois Filed Feb. 4, 1959, Ser. No. 791,213 9 Claims. (Cl. -15)This invention relates to apparatus for the removal of dust from papersuch as that used for newsprint. More specifically my invention relatesto the removal of dust from a paper web by creating an electrostaticcharge on a body and passing the paper Web over and in contact with thecharged body so that the electrostatic charge will attract the dust andthus remove it from the web.

In the processing of paper for use as newsprint a large amount of lintand dust is normally created, particularly in the slitting of the paperWeb, and such lint and dust deposits itself upon the web in the form offiber, fuzz, or whiskers. Such extraneous material often gathers intowads forming what are known as hickies on the paper sheet. These dustformations can seriously impair the printed surface, particularly in thecase of offset printing, since the hickies can be transferred to theblanket and in the printing process the imperfection in the printingresulting therefrom will be repeated on sheet after sheet in the sameplace. This necessitates frequent cleaning or washing of the blankets,plates and ink rollers, with consequent loss of time and increase inlabor.

Some mills use compressed air, a vacuum or a brush to remove the dustand lint from the paper, but due to the high static charge which usuallyexists on the paper, there is a tendency for dust particles or lint tostick to the surface so that they are not effectively removed by themethods heretofore known. I have provided a method and apparatus forslitting paper webs so as to minimize the formation of lint and dust asset forth in my application, Serial No. 609,215, filed September 11,1956, now Patent No. 2,989,882, but even when this method is employed itis likely that some dust and lint will be deposited upon the paperduring the slitting process. If apparatus of the present invention beused for removing dust from a paper Web in conjunction with theinvention disclosed in my application referred to above then the amountof dust or lint remaining on the paper at the time the Web enters theprinting press would be so negligible as not to pose a serious problem.Furthermore even i used alone the present invention would materiallyalleviate the problem.

One object of this invention is to provide apparatus for removing lintand dust from a paper web so that paper so processed will be suitablefor use in oifset printing and other printing processes.

Another object of this invention is to provide an apparatus which isparticularly well suited for embodying my invention.

Other objects and advantages of my invention will be apparent from thefollowing description of a preferred embodiment thereof, taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a side elevational view of an apparatus embodying thestructural features of my invention.

FIG. 2 is an end elevational view of my apparatus taken along the line2-2 of FIG. 1.

FIG. 3 is an enlarged end elevational broken away, taken along the line3-3 of FIG. 1.

FIG. 4 is a top plan View thereof, taken along the line 44 of FIG. 3.

FIG. 5 is a sectional view thereof, partly broken away, taken along theline 5-5 of FIG. 3.

view, partly FIG. 6 is a sectional view of an alternative type ofapparatus embodying my invention.

FIG. 7 is a fragmentary elevational view taken along the line 77 of FIG.6.

Referring to FIG. 1 a roll of paper 1 is shown mounted on a rotatablysupported shaft 2. A web 3 from said roll is conducted over guide roller4 and upwards so as to pass between a guide roller 5 and anelectrostatically charged roller 6. The roller 6 has a positiveelectrostatic charge on it so that when the web 3 contacts such rollerthe negatively charged dust particles on the web are drawn from the weband deposited upon this roller. The substantially dust free web is thenconducted over guide rollers 7, 8, 9 and 10 after which it is feddirectly to the printing press (not shown).

The electrostatic charge on the roller 6 is produced in the followingmanner. Such roller is supported on a shaft 11 which is rotatablymounted in bearings 12 and 13 (see FIG. 4). The shaft 11 is rotated by amotor 14 (see FIG. 2) through a chain 15 which is connected to the shaft11 and to the power shaft 16 of the motor 14. Mounted adjacent to theroller 6 is an idler friction roller 17 (see FIGS. 1, 4 and 5) supportedby a shaft 18 which is rotatably mounted in bearings 19 and 29. Theroller 17 is mounted so as to contact roller 6 so that when the roller 6is rotated by the motor 14 and chain 15 the roller 17 will be rotated bythe roller 6. When the rollers 6 and 17 are in operation correspondingareas on the surfaces of each are continuously coming into contact andseparating and it is this cooperation between the rollers 6 and 17 inconjunction with the materials chosen for their respective surfaceswhich results in the production of a positive electrostatic charge uponthe roller 6.

In this preferred embodiment the roller 6 is manufactured frompolyethylene and the surface of roller 17 is manufactured from nylonfur. The rubbing of the polyethylene surface against the nylon fursurface will produce a positive electrostatic charge on the former.There are numerous other materials from which the rollers 6 and 17 mightbe manufactured such that rolling contact between the two would producea static charge. For example, the rollers 6 and 17 could bemanufactured, respectively, from the following materials: asbestos andmica, mica and wool, aluminum and india rubber, or ebonite and brass.Lists of substances arranged in such an order that when any two arerubbed together, the one higher in the list becomes positive withrespect to the other material are known as triboelectric series and itshould be understood that the materials for rollers 6 and 17 are to bechosen from such a list providing that these rollers are made ofdissimilar materials and the material chosen for roller 6 which is to bepositively charged is higher in the list than the material chosen forroller 17.

It will now be understood that when the rollers 6 and 17 are in motion apositive electrostatic charge is produced upon the rollers 6 and whenthe web 3 is conducted between rollers 5 and 6 so as to contact roller 6the lint and dust, deposited upon the web by previous processingoperations, being negatively charged, is attracted by the positivelycharged roller 6 which removes such dust from the web and deposits itupon the roller 17 through its contact with the latter.

Referring to FIGS. 1-5 it will be noted that the rollers 6 and 17 arecontained within an enclosure 24 which in this preferred embodiment ismanufactured from transparent Plexiglas. This enclosure confines thedust which is removed from the paper web such that it can be removed bya vacuum pump 21 which is connected to the enclosure 24 by a pipe 22 andexhaust dust 23 (see FIG. 5).

.a rubber belt 26 .around a pulley 25 which may be made of Lucite andwhich has its surface covered with a material such as polyethylene tape.The passing of the belt 26 around the pulley causes a negativeelectrostatic charge to be producedupon the pulley 25. The electrostaticcharge produced upon pulley 25 will be negative because 'of thematerials chosen for the belt 26 and the pulley 25 respectively. Sinceunlike charges attract each other the negatively charged pulley 25 tendsto attract positive charges through the small wire screen or brush 27which is mounted near said pulley but separated therefrom by the belt26. The positive charges attracted by the pulley 25 are thus depositedupon the belt 26.

The belt 26 passes over a second pulley 28 which in the embodiment beingdescribed may also be made of Lucite and is covered with a layer ofmaterial such as aluminum foil. The pulleys 25 and 28 are supported bythe shafts 29 and 30, respectively, and these shafts are rotatablymounted in bearings (not shown). The shaft 29 is rotated by suitablepower means (not shown) so that in operation the pulley 25 is rotatedcounter-clockwise to move the belt 26 upward on theright and downward onthe left (as shown in FIG. 6) and so that the pulley 28 through itscontact with said belt is also rotated in a counterclockwise direction.

As the belt 26 rotates and carries the positive electrostatic chargeupward the pulley 28 becomes positively charged, due to the fact thatportions of said pulley 28 are continuously brought first into intimatecontact and then separated from said belt, and because of its attractionfor negative charges the pulley 23 causes negative charges tobe'deposited upon the belt 26 which carries them downward (as shown inFIG. 6). The belt 26 is thus carrying positive charges upward andnegative charges downward.

A roller 31, which has a surface of material such as nylon fur, issupported by a shaft 32 which shaft is rotatably mounted in bearings(not shown), and the moving paper web 3 is passed from right to left (asshown in FIG. 6) between the roller 28 and the pulley 31 to a printing.press. The excess positive electrons which are carried upward on thebelt 26 are transferred through the paper web 3 to the nylon fur roller31 so that the roller 31 becomes charged with an excess of positiveelectrons. As the paper web is passed under the roller 31 the negativelycharged dust particles are removed from the top of the paper web 3 anddeposited upon the roller 31. A small wire screen 33 acts as a groundand discharges successive portions of the roller 31 as they passdirectly beneath said screen thus causing the dust to be removed fromsaid portions and drawn out through an exhaust duct 34 by vacuum means(not shown) without afiecting the positive charge upon that portion ofthe roller 31 which is in contact with the moving web 3.

Various materials other than those described above may be used for therollers 25 and 28. Thus the materials for the roller 25 which is to benegatively charged may be chosen from any triboelectric series such aspreviously referred to and the material chosen should be lower in saidseries than the belt material. The material chosen for the roller 28which is to be positively charged may be chosen from the triboelectricseries and this material should be higher in the series than the beltmaterial.

The apparatus described above is contained within an enclosure 36 and .asource of warm air is shown at 35 (see FIG. 6) so that the relativehumidity within said euclosure can be controlled so as to beapproximately 30% or less since higher humidities tend to prevent theformation of the neceessary charges at the pulleys.

It should be noted that in both of the embodiments described hereinprovision is made for removal of lint and dust from only one side of themoving paper web. It should, of course, be understood that a completedust removal system would require two oppositely-disposed units witheach arranged to clean a different side of the web.

This invention can, of course, be applied in various ways and thepresent description should, therefore, be regarded as disclosing only anillustrative embodiment of the invention from which no unnecessarylimitations should be implied.

I claim:

1. An apparatus for removing the lint and dust from a moving paper webcomprising: a pair of rollers made of dissimilar materials chosen from atriboelectric series, said rollers being rotatably mounted on parallelaxes so as to be in contact with each other in such manner that rotationof one of said rollers will effect rotation of the other; means forrotating one of said rollers so as to produce rolling contact betweensaid rollers and thus produce electrosta'tic charges on one of saidrollers; and means for bringing a paper web into intimate contact withthat roller in the pair which has been positively charged due to saidrolling contact whereby any lint and dust adhering to said web will beattracted by said positively charged roller and removed thereby.

2. An apparatus for removing the lint and dust from a moving paper webcomprising: a pair of rollers made of dissimilar materials chosen from atriboelectric series, said rollers being rotatably mounted on parallelaxes so as to be in contact with each other whereby rotation of one ofsaid rollers will efiect rotation of the other; means for rotating oneof said rollers so as to produce rolling contact between said rollers;and means for conducting a paper web over and in intimate contact withthat roller in the pair which has been positively charged due to saidrolling contact so that said web comes into intimate contact with saidpositively charged roller.

3. An apparatus for removing the lint and dust from a moving paper webcomprising: a pair of rollers made of dissimilar materials chosen from atriboelectric series, said rollers being rotatably mounted on parallelaxes so as to be in contact with each other whereby rotation of one ofsaid rollers will effect rotation of the other; means for rotating oneof said rollers so as to produce rolling contact between said rollers;means for conducting a paper web over that roller in the pair which hasbeen positively charged due to said rolling contact so that said web isbrought into intimate contact with said positively charged roller; meanswhich substantially enclose said pair of rollers and yet permit contactbetween said web and said positively charged roller; an exhaust ductconnected with said enclosure; and means for removing the lint and dustcollected in said enclosure out through said exhaust duct.

4. An apparatus for removing the lint and dust from a moving paper webcomprising: a pair of spaced rollers mounted on parallel axes; a beltmounted on said rollers such that rotation of one of said rollers willcause rotation of the other, said belt, said first roller, and saidsecond roller all being made of dissimilar materials so chosen thatcontact between said belt and said rollers will pro duce a negativecharge on the first of said rollers and a positive charge upon thesecond; means for rotating one of said rollers so as to continuouslyeffect first intimate contact and then separation between portions ofsaid first roller and said belt and between portions of said secondroller and said belt so as to produce electrostatic charges on saidrollers whereby the positive charges attracted to said belt by saidfirst roller are carried towards said second roller by said belt and thenegative charges attracted to said belt by said second roller arecarried towards said first roller by said belt; a third roller, mountedadjacent .to said second roller on an axis parallel to the axis of saidsecond roller, for collecting the positive charges produced by saidfirst and second rollers and said belt; and means for bringing a paperweb into intimate contact with said third roller whereby any lint anddust adhering to said Web will be attracted by said third roller andremoved thereby.

5. An apparatus for removing the lint and dust from a moving paper webof the type described in claim 4 comprising: an enclosure whichsubstantially encloses said three rollers and yet permits said web to beconducted over the third roller; means for discharging portions of saidthird roller without affecting the charge on that portion which is incontact with said web; an exhaust duct connected with said enclosure;means for removing the dust collected by said third roller out throughsaid exhaust duct; and a source of warm air Within said enclosure.

6. Apparatus for removing the lint and dust from a paper Web comprising:a plurality of rollers rotatably mounted on parallel axes; means forrotating said rollers; means for producing a positive electrostaticcharge on one of said rollers, said last-mentioned means comprising amember arranged to frictionally contact said last-mentioned roller andbeing made of a material dissimilar to the material of such roller, saidmaterials being chosen from a triboelectric series; and means fordirecting the web between two of said rollers in intimate contact withthe one that is positively charged whereby any lint and dust adhering tothe web will be attracted to and removed by said positively chargedroller.

7. In an apparatus for removing lint and dust from a moving paper web asset forth in claim 4: an enclosure for said third roller; and means forremoving from said enclosure the lint and dust collected by said thirdroller.

8. An apparatus for removing lint and dust from a paper web as ittravels to a printing press or the like comprising: a first and secondroller between which the web is passed and by which it is engaged; athird roller in contact with said second roller, said third and secondrollers being made of dissimilar materials chosen from a triboelectricseries; and means for rotating said three rollers whereby a positiveelectrostatic charge is imparted to said second roller by said thirdroller and lint and dust is collected from the paper web onto saidsecond roller.

9. An apparatus for removing lint and dust from a paper web as ittravels to a printing press or the like comprising: a first and secondroller between which the web is passed and by which it is engaged; athird roller in contact with said second roller, said third and secondrollers being made of dissimilar materials chosen from a tribeelectricseries; means for rotating said three rollers whereby a positiveelectrostatic charge is imparted to said second roller by said thirdroller and lint and dust is collected from the paper web onto saidsecond roller; an enclosure for said second and third rollers; and meansfor exhausting from said enclosure the lint and dust collected by saidsecond roller.

References Cited in the file of this patent UNITED STATES PATENTS2,013,714 Judge Sept. 10, 1935 2,151,273 Hess Mar. 21, 1939 2,825,078Bugler et al. Mar. 4, 1958 2,832,977 Walkup et a1 May 6, 1958 2,848,727Johnson Aug. 26, 1958 2,884,348 Kulesza Apr. 28, 1959 2,894,744 SchulzeJuly 14, 1959 2,894,860 Engelhardt July 14, 1959 2,920,987 Landry et al.Jan. 12, 1960 2,980,933 Schwartz et al. Apr. 25, 1961

1. AN APPARATUS FOR REMOVING THE LINT AND DUST FROM A MOVING PAPER WEB COMPRISING: A PAIR OF ROLLERS MADE OF DISSIMILAR MATERIALS CHOSEN FROM A TRIBOELECTRIC SERIES, SAID ROLLERS BEING ROTATABLY MOUNTED ON PARALLEL AXES SO AS TO BE IN CONTACT WITH EACH OTHER IN SUCH MANNER THAT ROTATION OF ONE OF SAID ROLLERS WILL EFFECT ROTATION OF THE OTHER; MEANS FOR ROTATING ONE OF SAID ROLLERS SO AS TO PRODUCE ROLLING CONTACT BETWEEN SAID ROLLERS AND THUS PRODUCE ELECTROSTATIC CHARGES ON ONE OF SAID ROLLERS; AND MEANS FOR BRINGING A PAPER WEB INTO INTIMATE CONTACT WITH THAT ROLLER IN THE PAIR WHICH HAS BEEN POSITIVELY CHARGED DUE TO SAID ROLLING CONTACT WHEREBY ANY LINT AND DUST ADHERING TO SAID 